Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Scientists Glimpse Nanobubbles on Super Non-Stick Surfaces

In this picture, the central image is the optical profile of a water drop placed on "nanopitted" silicon; the right image is a scanning electron micrograph of the nanocavities; and the left image is a cartoon illustrating the nanobubbles' shape as inferred from x-ray measurements.
In this picture, the central image is the optical profile of a water drop placed on "nanopitted" silicon; the right image is a scanning electron micrograph of the nanocavities; and the left image is a cartoon illustrating the nanobubbles' shape as inferred from x-ray measurements.

Abstract:
Could lead to design of water-shedding materials for applications in energy, medicine, and more

Scientists Glimpse Nanobubbles on Super Non-Stick Surfaces

Upton, NY | Posted on February 24th, 2010

Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have obtained the first glimpse of miniscule air bubbles that keep water from wetting a super non-stick surface. Detailed information about the size and shape of these bubbles — and the non-stick material the scientists created by "pock-marking" a smooth material with cavities measuring mere billionths of a meter — is being published online today in the journal Nano Letters.

"Our results explain how these nanocavities trap tiny bubbles which render the surface extremely water repellent," said Brookhaven physicist and lead author Antonio Checco. The research could lead to a new class of non-stick materials for a range of applications, including improved-efficiency power plants, speedier boats, and surfaces that are resistant to contamination by germs.

Non-stick surfaces are important to many areas of technology, from drag reduction to anti-icing agents. These surfaces are usually created by applying coatings, such as Teflon, to smooth surfaces. But recently — taking the lead from observations in Nature, notably the lotus leaf and some varieties of insects — scientists have realized that a bit of texture can help. By incorporating topographical features on surfaces, they've created extremely water repellant materials.

"We call this effect ‘superhydrophobicity,'" said Brookhaven physicist Benjamin Ocko. "It occurs when air bubbles remain trapped in the textured surfaces, thereby drastically reducing the area of liquid in contact with the solid." This forces the water to ball up into pearl shaped drops, which are weakly connected to the surface and can readily roll off, even with the slightest incline.

"To get the first glimpse of nanobubbles on a superhydrophobic surface we created a regular array of more than a trillion nano-cavities on an otherwise flat surface, and then coated it with a wax-like surfactant," said Charles Black, a physicist at Brookhaven's Center for Functional Nanometerials.

This coated, nanoscale textured surface was much more water repellant than the flat surface alone, suggesting the existence of nanobubbles. However, because the nanoscale is not accessible using ordinary microscopes, little is known about these nanobubbles.

To unambiguously prove that these ultra-small bubbles were present, the Brookhaven team carried out x-ray measurements at the National Synchrotron Light Source. "By watching how the x-rays diffracted, or bounced off the surface, we are able to image extremely small features and show that the cavities were mostly filled with air," said Brookhaven physicist Elaine DiMasi.

Checco added, "We were surprised that water penetrates only about 5 to 10 nanometers into the cavities — an amount corresponding to only 15 to 30 layers of water molecules — independent of the depth of the cavities. This provides the first direct evidence of the morphology of such small bubbles."

According to the scientists' observations, the bubbles are only about 10 nanometers in size — about ten thousand times smaller than the width of a single human hair. And the team's results conclusively show that these tiny bubbles have nearly flat tops. This is in contrast to larger, micrometer-sized bubbles, which have a more rounded top.

"This flattened configuration is appealing for a range of applications because it is expected to increase hydrodynamic slippage past the nanotextured surface," Checco said. "Moreover, the fact that water hardly penetrates into the nano-textures, even if an external pressure is applied to the liquid, implies that these nanobubbles are very stable."

Therefore, in contrast to materials with larger, micrometer-sized textures, the surfaces fabricated by the Brookhaven team may exhibit more stable superhydrophobic properties.

"These findings provide a better understanding of the nanoscale aspects of superhydropobicity, which should help to improve the design of future superhydrophobic non-stick surfaces," Checco said.

This research is funded by the DOE Office of Science. Tommy Hofmann, a former Brookhaven physicist now at Helmholtz Zentrum Berlin, also contributed to this work.

Related Links

Paper: Morphology of Air Nanobubbles Trapped at Hydrophobic Nanopatterned Surfaces
pubs.acs.org/doi/abs/10.1021/nl9042246


####

About Brookhaven National Laboratory
One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

For more information, please click here

Contacts:
Karen McNulty Walsh
(631) 344-8350

Mona S. Rowe
(631) 344-5056

Copyright © Brookhaven National Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Tiny nanoclusters could solve big problems for lithium-ion batteries February 21st, 2017

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

Nominations Invited for $250,000 Kabiller Prize in Nanoscience: Major international prize recognizes a visionary nanotechnology researcher February 20th, 2017

Breakthrough with a chain of gold atoms: In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport February 20th, 2017

Marine/Watercraft

Transparent gel-based robots can catch and release live fish: Made from hydrogel, robots may one day assist in surgical operations, evade underwater detection February 2nd, 2017

NIST-made 'sun and rain' used to study nanoparticle release from polymers October 5th, 2016

New material to revolutionize water proofing September 12th, 2016

Tracing barnacle's footprint August 19th, 2016

Govt.-Legislation/Regulation/Funding/Policy

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Engineers shrink microscope to dime-sized device February 17th, 2017

Francis Alexander Named Deputy Director of Brookhaven Lab's Computational Science Initiative February 16th, 2017

Good vibrations help reveal molecular details: Rice University scientists combine disciplines to pinpoint small structures in unlabeled molecules February 15th, 2017

Possible Futures

Tiny nanoclusters could solve big problems for lithium-ion batteries February 21st, 2017

Nominations Invited for $250,000 Kabiller Prize in Nanoscience: Major international prize recognizes a visionary nanotechnology researcher February 20th, 2017

Breakthrough with a chain of gold atoms: In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport February 20th, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Announcements

Tiny nanoclusters could solve big problems for lithium-ion batteries February 21st, 2017

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

Oxford Instruments announces Dr Brad Ramshaw of Cornell University, as winner of the 2017 Lee Osheroff Richardson Science Prize February 20th, 2017

Breakthrough with a chain of gold atoms: In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport February 20th, 2017

Energy

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

In-cell molecular sieve from protein crystal February 14th, 2017

NREL research pinpoints promise of polycrystalline perovskites February 8th, 2017

Nanobiotechnology

Good vibrations help reveal molecular details: Rice University scientists combine disciplines to pinpoint small structures in unlabeled molecules February 15th, 2017

In-cell molecular sieve from protein crystal February 14th, 2017

Cedars-Sinai, UCLA Scientists Use New ‘Blood Biopsies’ With Experimental Device to Speed Cancer Diagnosis and Predict Disease Spread: Leading-Edge Research Is Part of National Cancer Moonshot Initiative February 13th, 2017

Nanobiotix appoints senior executive from pharmaceutical industry, as Chief Operating Officer: Oncology industry veteran to oversee operations and product commercialization February 8th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project